A103297 Number of different lengths that perfect rulers with n segments can have.

1, 1, 2, 3, 3, 4, 4, 6, 6, 7, 7, 7, 8, 10, 11, 11, 11, 11, 11, 13, 14, 15, 15, 16, 14, 19

Offset: 0

Author

Peter Luschny, Feb 28 2005

Keywords

• nonn
• hard

Comments

For definitions, references and links related to complete rulers see A103294.

Examples

			a(5)=4 because a perfect ruler with 5 segments may have the length 10, 11, 12 or 13.
		

Links

• F. Schwartau, Y. Schröder, L. Wolf and J. Schoebel, MRLA search results and source code, Nov 6 2020.
• F. Schwartau, Y. Schröder, L. Wolf and J. Schoebel, Large Minimum Redundancy Linear Arrays: Systematic Search of Perfect and Optimal Rulers Exploiting Parallel Processing, IEEE Open Journal of Antennas and Propagation, 2 (2021), 79-85.
• Index entries for sequences related to perfect rulers.

Crossrefs

Cf. A103298.

Formula

a(n) = A004137(n+1) - A004137(n) for n>= 1.

Extensions

Term a(19) corrected and terms a(20)-a(25) added by Fabian Schwartau, Yannic Schröder, Lars Wolf, Joerg Schoebel, Feb 23 2021